docs: def process_like(proc):
      """Make an exact clone of a process, including state and all subprocesses.
  
      The creation date is updated.
  
      :param proc:    process
      :type proc:     :class:`~climlab.process.process.Process`
      :return:        new process identical to the given process
      :rtype:         :class:`~climlab.process.process.Process`
  
      :Example:
  
          ::
  
              >>> import climlab
              >>> from climlab.process.process import process_like
  
              >>> model = climlab.EBM()
              >>> model.subprocess.keys()
              ['diffusion', 'LW', 'albedo', 'insolation']
  
              >>> albedo = model.subprocess['albedo']
              >>> albedo_copy = process_like(albedo)
  
              >>> albedo.creation_date
              'Thu, 24 Mar 2016 01:32:25 +0000'
  
              >>> albedo_copy.creation_date
              'Thu, 24 Mar 2016 01:33:29 +0000'
  
      """
      newproc = copy.deepcopy(proc)
      newproc.creation_date = time.strftime("%a, %d %b %Y %H:%M:%S %z",
                                            time.localtime())
      return newproc